Timken Super Precision Bearings for Machine Tool Applications

A
ENGINEERING
Timken super precision ball bearings are universal flush ground,
which allows for DB (back-to-back), DF (face-to-face), or DT
(tandem) mounting of all matched duplex sets. This does not need
to be specified during order.
Preload Level
The internal condition of a preloaded ball bearing is similar to
that of one in operation under axial load. This initial axial load
serves to decrease markedly the axial and radial deflections when
subsequent operational loads are imposed on the bearing assembly.
Preload levels limit change in contact angle at very high speeds, and
prevent ball skidding under very high acceleration and speed.
In many cases, the amount of bearing preload is a trade-off between
having the desired degree of rigidity and reducing any adverse effect
preloading has on the equipment. If the operating speed is high, a
heavy preload can lead to excessively high operating temperatures,
which may result in bearing damage. To match general performance
requirements, four classes of ball bearing preloads are used –
extra-light, light, medium and heavy. To maximize performance,
Timken can design specially preloaded super precision ball
bearings.
Sealed Ball Screw Support Bearings
Available in flanged (MMF) and non-flanged (MMN) series, these
designs simplify installation for both standard and rotating nut
mountings. The flanged version eliminates the need for external
clamping of the outer ring. The standard version is the sealed duplex
configuration, but both series may be ordered with seals or shields
in either a duplex or quad set arrangement.
Wear/Debris-Resistant Material
Advanced bearings can resist debris wear for improved machine
tool performance and service life. Timken super precision bearings
with WearEver technology combine a special high-alloy steel with
ceramic balls to provide superior performance and cutting quality
for high-speed applications. Extended capabilities help improve
machine efficiency and utilization while reducing secondary
finishing operations and downtime.
This unique, wear/debris-resistant steel was specifically
incorporated into the bearing design to withstand damage from
hard contaminants, a primary cause for shortened bearing life.
Studies have shown that bearings with this advanced material can
deliver up to ten times the standard service life in the presence of
hard contamination. This represents a significant advancement in
high-speed machining productivity and improved product quality.
Consult your Timken representative for availability.
Other
Bearings may be customized to specify lubrication type,
special coding, special part marking, etc. Contact your Timken
representative for more information.
2 MM C 91 04 WI CR DUL A4437
FS637
A4437 = Special coding requirement
FS637 = Kluber isoflex NBU 15 Grease
Fig. 22. Examples of non-standard specification numbers.
30 TIMKEN MACHINE TOOL CATALOG